From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout04.his.huawei.com (canpmsgout04.his.huawei.com [113.46.200.219]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E728E3BF300; Thu, 22 Jan 2026 11:42:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.219 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769082139; cv=none; b=c4jVjixY7vEMKiUUuaTXjzxkS7bOf+vkGtiZVByf4/dJpFs+KMwW9V3dJKN4XZVV+kfpmRSX4oyOtDrnmcQ/2l2jYi44RfTqZvGqtc4bxKXNeiQyx9AivhhyJVuFPco3Drj/M/ozTk6J066QvKuHHl2i00684ACPJ9cPM02nDvE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769082139; c=relaxed/simple; bh=BzROj+qPjwn10Wcma/Olj18t2mzIjhUK3GYki215h+8=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=HR3T6f+ioI5bVZfkcT+yavMfg72e7y4GqVg0KKiOvo3dBwQngY7CbDPo6yp2Etr7boOP0WLfwD+P07VdMr2w1qA4AuTq7mN5w+P6N8wRwZ62Tf23s0HKUJ+AphLz2G4ZkaGF32KzcBrzDSdod9NjgAluobQLnRorVBwE6T2OfGU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=XC7a8yEZ; arc=none smtp.client-ip=113.46.200.219 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="XC7a8yEZ" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=h5IO1II72SHvth+63/+3XlMGErqZm+GjmL10qJGkNv0=; b=XC7a8yEZdC7zIgkgPK+S1MAfcQsfB27AFE7g5ZpXZyCtulOyzPlnTX6pwIVmtfOLGB/TCimUs ct20hV+y4kPWZVNVF98vHQMjNQCOnpLFo7/dVYu2TIisB7QjQYMo11UgeCX7UUnkJ6LCYy4D1hN zWYSjEQa9LNGQM7MYw6BYOw= Received: from mail.maildlp.com (unknown [172.19.162.223]) by canpmsgout04.his.huawei.com (SkyGuard) with ESMTPS id 4dxfGB36X9z1prKl; Thu, 22 Jan 2026 19:38:42 +0800 (CST) Received: from kwepemf200001.china.huawei.com (unknown [7.202.181.227]) by mail.maildlp.com (Postfix) with ESMTPS id C8F2340569; Thu, 22 Jan 2026 19:42:08 +0800 (CST) Received: from [10.67.121.90] (10.67.121.90) by kwepemf200001.china.huawei.com (7.202.181.227) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 22 Jan 2026 19:42:07 +0800 Message-ID: <0ea13064-be34-449c-9dd0-760333111da3@huawei.com> Date: Thu, 22 Jan 2026 19:42:07 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 4/9] ACPI: CPPC: Add cppc_get_perf() API to read performance controls To: Pierre Gondois , Sumit Gupta CC: , , , , , , , , , , , , , , , , , , , , , , , , References: <20260120145623.2959636-1-sumitg@nvidia.com> <20260120145623.2959636-5-sumitg@nvidia.com> <7f0b280d-9c22-46dc-a924-a85591e1034d@huawei.com> <5afea521-7d80-4e72-8809-77af60b0d957@arm.com> From: "zhenglifeng (A)" In-Reply-To: <5afea521-7d80-4e72-8809-77af60b0d957@arm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems200001.china.huawei.com (7.221.188.67) To kwepemf200001.china.huawei.com (7.202.181.227) On 2026/1/22 19:30, Pierre Gondois wrote: > > On 1/22/26 09:56, zhenglifeng (A) wrote: >> On 2026/1/20 22:56, Sumit Gupta wrote: >>> + >>> +    if (CPC_SUPPORTED(desired_perf_reg)) >>> +        cpc_read(cpu, desired_perf_reg, &desired_perf); >>> +    perf_ctrls->desired_perf = desired_perf; >> desired_perf_reg is not an optional one, so it has to be supported. > > The ACPI spec seems to say it is optional under some circumstances. > > Cf: > """ > This register is optional when OSPM > indicates support for CPPC2 in the platform-wide _OSC > capabilities and the Autonomous Selection Enable reg- > ister is Integer 1 > """ > > > Maybe it is ok to let this check here and to a more complex verification > in acpi_cppc_processor_probe() Right. My mistake. >